Catálogo de publicaciones - revistas

<jats:title>Describing an exotic magnetic transition</jats:title> <jats:p>Phase transitions can be caused by temperature fluctuations or, more exotically, by quantum fluctuations at zero temperature. To describe some of these quantum phase transitions, researchers came up with a complex theory called deconfined quantum criticality.</jats:p> <jats:p> However, subsequent numerical simulations were inconsistent with some of the predictions of the theory, leading to a debate on its validity. By using quantum Monte Carlo simulations, Shao <jats:italic>et al.</jats:italic> show that it is possible to reconcile numerics with the theory for a specific model of 2D quantum magnetism. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6282" page="213" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aad5007">213</jats:related-article> </jats:p>

<jats:title>Every brain is different</jats:title> <jats:p> We all differ in how we perceive, think, and act. What drives individual differences in evoked brain activity? Tavor <jats:italic>et al.</jats:italic> applied computational models to functional magnetic resonance imaging (fMRI) data from the Human Connectome Project. Brain activity in the “resting” state when subjects were not performing any explicit task predicted differences in fMRI activation across a range of cognitive paradigms. This suggests that individual differences in many cognitive tasks are a stable trait marker. Resting-state functional connectivity thus already contains the repertoire that is then expressed during task-based fMRI. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6282" page="216" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aad8127">216</jats:related-article> </jats:p>

<jats:title>Not just turnout, but turnaround matters</jats:title> <jats:p>In the last several U.S. presidential elections, the campaign mantra has focused on making sure that voters already aligned with one's candidate do get out to vote. There is a long history of unsuccessful efforts to change people's attitudes. Nevertheless, Broockman and Kalla conducted a field experiment showing that Miami voters shifted their attitudes toward transgender individuals and maintained those changed positions for 3 months (see the Perspective by Paluck).</jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6282" page="220" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aad9713">220</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6282" page="147" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf5207">147</jats:related-article> </jats:p>

<jats:title>A more sensitive climate system</jats:title> <jats:p> How much global average temperature eventually will rise depends on the Equilibrium Climate Sensitivity (ECS), which relates atmospheric CO <jats:sub>2</jats:sub> concentration to atmospheric temperature. For decades, ECS has been estimated to be between 2.0° and 4.6°C, with much of that uncertainty owing to the difficulty of establishing the effects of clouds on Earth's energy budget. Tan <jats:italic>et al.</jats:italic> used satellite observations to constrain the radiative impact of mixed phase clouds. They conclude that ECS could be between 5.0° and 5.3°C—higher than suggested by most global climate models. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6282" page="224" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aad5300">224</jats:related-article> </jats:p>

<jats:title>Oncogene control of antitumor immunity</jats:title> <jats:p> Recent clinical success of cancer immunotherapy has intensified interest in how tumors normally evade the immune response. Whether and how oncogenes contribute to this process are not well understood. In a study of mice, Casey <jats:italic>et al.</jats:italic> found that the <jats:italic>MYC</jats:italic> oncogene, which is aberrantly activated in many human cancers, up-regulates the expression of genes encoding proteins that dampen the antitumor response. These include two proteins that are often overexpressed on tumor cells and that serve as immune checkpoints. One of them (PDL1) sends to the immune system a “don't find me” signal, and the other (CD47) sends a “don't eat me” signal. Thus, therapies aimed at suppressing <jats:italic>MYC</jats:italic> may help promote an immune response against tumors. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6282" page="227" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aac9935">227</jats:related-article> </jats:p>

<jats:title> Taking control of cellular NAD <jats:sup>+</jats:sup> concentrations </jats:title> <jats:p> Cellular concentrations of the nicotinamide adenine dinucleotide (NAD <jats:sup>+</jats:sup> ) are critical for proper metabolism and are often altered in aging and disease. To enable better understanding of these processes, Titov <jats:italic>et al.</jats:italic> altered the concentration of NAD <jats:sup>+</jats:sup> in particular cellular compartments. They did this through expression of a bacterial enzyme targeted to specific compartments of human cells in culture. Their experiments emphasize the important role of the electron transport chain in redox transfer of electrons to NADH, rather than proton pumping, in mitochondrial pathogenesis. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6282" page="231" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aad4017">231</jats:related-article> </jats:p>

<jats:title>Denisovan DNA retained in Melanesians</jats:title> <jats:p> Modern humans carry remnants of DNA from interbreeding events with archaic lineages, such as Neandertals. However, people from Oceania also retain genes from a second ancient lineage, the Denisovans. Vernot <jats:italic>et al.</jats:italic> surveyed archaic genomic sequences in a worldwide sample of modern humans, including 35 individuals from the Melanesian Islands. All non-African genomes surveyed contained Neandertal DNA, but a significant Denisovan component was found only in the Melanesians. Reconstruction of this genetic history suggests that Neandertals bred with modern humans multiple times, but Denosivans only once, in ancestors of modern-day Melanesians. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6282" page="235" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aad9416">235</jats:related-article> </jats:p>

<jats:title>How biomolecules fold</jats:title> <jats:p> In order to fold, biomolecules must search a conformational energy landscape to find low-energy states. There are peaks in the landscape where the molecules must occupy unstable conformations for a short time. Neupane <jats:italic>et al.</jats:italic> used optical tweezers to observe these transition paths directly for single nucleic acid and protein molecules (see the Perspective by Wolynes). They measured a distribution of times taken to cross the transition path and found that the shape of the distribution agrees well with theory that assumes one-dimensional diffusion over the landscape. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6282" page="239" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aad0637">239</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6282" page="150" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf6626">150</jats:related-article> </jats:p>

<jats:title>Macrophages block tumors' spread</jats:title> <jats:p> Tumors constantly communicate with their surrounding tissue and the immune system. One way tumors likely do this is by secreting extracellular vesicles (tEVs), which can carry bits of the tumor to distant sites in the body. Pucci <jats:italic>et al.</jats:italic> tracked tEVs in tumor-bearing mice and people and studied how they affect cancer progression. They found that tEVs disseminate through lymph to nearby lymph nodes, where a specialized population of macrophages largely block any further travel. This barrier breaks down, however, as cancer progresses and also in the face of certain therapies. The tEVs can then penetrate lymph nodes, where they interact with B cells that promote further tumor growth. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6282" page="242" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf1328">242</jats:related-article> </jats:p>

<jats:p> The detection of cancer in the body, particularly early in its progression, can provide life-saving information for subsequent treatment. Researchers are now demonstrating that increases in the speed, accuracy, and resolution of next-generation sequencing (NGS) have made it possible to sequence minute amounts of DNA from scarce and rare samples, such as circulating cancer cells from liquid biopsies or archival tissue in formalin-fixed paraffin embedded (FFPE) samples. Taking this to the next level, NGS panels enable targeted sequencing of a small number of cancer-specific genes that can aid in quickly identifying and categorizing a particular cancer. This seminar will focus on the development and use of cancer detection panels for FFPE/liquid biopsy samples. Relying on their experience in both research and clinical settings, our panelists will discuss the challenges of designing, developing, analytically validating, and employing targeted NGS panels in translational research laboratories. The dramatic potential for future applications of NGS panels in a clinical setting will also be discussed. <jats:list list-type="bullet"> <jats:list-item> <jats:p> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://webinar.sciencemag.org/webinar/archive/characterizing-cancers-liquid-biopsies-and-ffpe-samples">View the Webinar</jats:ext-link> </jats:p> </jats:list-item> </jats:list> </jats:p>